SOLUTION: PLEASE HELP!!! I need help solving the following problems: 1. y=2x+7 y=5x+4 2. 3x-2y=0 x+y=-5 3. 4x+3y=-3 2x+y=-1 4. 2x-4y= 3.8 3x-y=17.7 solve al

Algebra ->  Test -> SOLUTION: PLEASE HELP!!! I need help solving the following problems: 1. y=2x+7 y=5x+4 2. 3x-2y=0 x+y=-5 3. 4x+3y=-3 2x+y=-1 4. 2x-4y= 3.8 3x-y=17.7 solve al      Log On


   

Question 106344: PLEASE HELP!!! I need help solving the following problems:
1. y=2x+7
y=5x+4
2. 3x-2y=0
x+y=-5
3. 4x+3y=-3
2x+y=-1
4. 2x-4y= 3.8
3x-y=17.7
solve all by using substitution!
Answer by elima(1433) About Me  (Show Source):
You can put this solution on YOUR website!
1. y=2x+7
y=5x+4
2x%2B7=5x%2B4
2x-5x=4-7
-3x=-3
x=1
------------------
y=2%281%29%2B7
y=2%2B7
y=9
====================
2. 3x-2y=0
x+y=-5
x=-5-y
3%28-5-y%29-2y=0
-15-3y-2y=0
-5y-15=0
-5y=15
y=-3
------------------
x%2B%28-3%29=-5
x=-5%2B3
x=-2
=========================
3. 4x+3y=-3
2x+y=-1
y=-1-2x
4x%2B3%28-1-2x%29=-3
4x-3-6x=-3
-2x-3=-3
-2x=0
x=0
-------------------
4%280%29%2B3y=-3
3y=-3
y=-1
===========================
4. 2x-4y= 3.8
3x-y=17.7
y=3x-17.7
2x-4(3x-17.7)=3.8}}}
2x-12x%2B70.8=3.8
-10x=-67
x=6.7
--------------------
2%286.7%29-4y=3.8
13.4-4y=3.8
-4y=-9.6
y=2.4
:)